Photosynthesis and Harvest of Deltoid Synurus (Synurus delitodes) under Three Different Light Environments

Many recent studies have reported on the properties of Deltoid synurus (Synurus deltoides), such as antimutation, antioxidant, and anti-inflammatory properties (Ham et al., 1997; Lee, 2003; Woo et al., 2010; Park et al., 2004; Jung et al., 2008). It contains β-cubebene and caryophyllene (Lee et al., 2012). This plant was acknowledged as a well-being food. Therefore, we researched the photosynthesis and harvest of Synurus deltoides under different light environment for high quality and yield. Synurus deltoides seeds were sown in 105 cells tray-pot in March 2012 and raised in the grass house. In May, these were planted in a 30×20 cm field. Shading treatment was carried out in the last ten days of the May, using 35% and 55% shading net. The light density and temperature under the different shading treatments was measured at 1 meter from the ground from May to September. We examined the hardness of leaves, photosynthesis, and yield under different shading. The data were analyzed by SPSS Statistics Program (Version 19.0) and Duncan's multiple range test. Harvest weight per plant grown under 0%, 35%, and 55% shading treatments was 35.9 g, 52.6 g and 21.1 g, respectively. The hardness under 35% shading was 1.8 kg/cm² compared with 2.3 kg/cm² under non-shading. The maximum photosynthesis rate was high under non-shading and 35% shading; 12.9 and 12.6 µmol·m^-2·s^-1 of  CO₂, respectively. The dark respiration under 35% shading was 22.2 µmol·m^-2·s^-1 compared with 28.5 µmol·m^-2·s^-1 under non-shading. The result indicated that the proper shading was 35% for high yield and quality of Synurus deltoides.